66151808809 has 2 divisors, whose sum is σ = 66151808810. Its totient is φ = 66151808808.

The previous prime is 66151808803. The next prime is 66151808819. The reversal of 66151808809 is 90880815166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52615184400 + 13536624409 = 229380^2 + 116347^2 .

It is a cyclic number.

It is not a de Polignac number, because 66151808809 - 2¹¹ = 66151806761 is a prime.

It is not a weakly prime, because it can be changed into another prime (66151808803) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33075904404 + 33075904405.

It is an arithmetic number, because the mean of its divisors is an integer number (33075904405).

Almost surely, 2^66151808809 is an apocalyptic number.

It is an amenable number.

66151808809 is a deficient number, since it is larger than the sum of its proper divisors (1).

66151808809 is an equidigital number, since it uses as much as digits as its factorization.

66151808809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 829440, while the sum is 52.

The spelling of 66151808809 in words is "sixty-six billion, one hundred fifty-one million, eight hundred eight thousand, eight hundred nine".